ANGLE-RESOLVED PHOTOEMISSION FROM YBA2CU3O7 - SIGNATURE OF CUO2 PLANE BANDS

We have carried out polarization dependent first principles calculations of the angle-resolved photoemission (ARPES) spectra within the local-density approximation (LDA) based band theory framework for the YBa2Cu3O7(001)-surface for k(parallel-to)-values along the GAMMAS line for all six possible ideal terminations of the lattice, together with parallel ARPES measurements. The theoretically predicted intensity and polarization dependence of the spectral feature arising from the CuO2 Plane bands near the Fermi energy is in remarkable overall accord with the measurements, giving confidence in the interpretation of the experimental data as being representative of the-bulk CuO2 bands. These results suggest that the LDA-based wave-functions implicit in the theory reasonably describe the physical situation at least near the Fermi energy, some renormalization of the quasi-particle spectrum notwithstanding. The question of surface termination is discussed; the present study favors the Y123(001)-surface to involve BaO topmost layer followed by the CuO2 plane layer.